Geographic information (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segments, Geographical Areas [Abstract]
Number of operating segments \| segment	1
Segment Reporting Information [Line Items]
Total assets	$ 1,623,782	$ 1,119,222
Property and equipment, net	21,549	12,694
Revenue	306,980	264,734	$ 194,392
United States
Segment Reporting Information [Line Items]
Total assets	1,508,055	1,013,977
Property and equipment, net	19,656	10,497
Revenue	116,676	93,694
Non-US
Segment Reporting Information [Line Items]
Total assets	115,727	105,245
Property and equipment, net	1,893	2,197
Revenue	$ 190,304	$ 171,040

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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